WP5: Air Quality Forecasting

Bas Mijling

Ronald van der A

Arjan LampeAMFIC Progress Meeting ● Barcelona ● 24 June 2009

AMFIC Work Package 5

5.1 Implementation of a chemical transport model on a 0.25 degree resolution

5.2 Model improvements, especially the incorporation of aerosols in the model

5.3 A better emission database will be incorporated in the model. If possible, this database will be improved based on retrieval-model comparisons

5.4 Implementation of an operational chemical weather forecast service

Overview

1. Implementation and use of Chimere model

2. Validation; High nocturnal values

3. Future steps

1Implementation Chimere model

Overview Chimere

output

CHIMERE

ECMWFmeteo

MELCHIOR scheme44 species120 reactions

INTEX-B2006 inventory

GLGC database1 x 1 km²

emissions

monthly averagesgas phase: LMDZ-INCA2aerosol: GOCART

boundaryconditions

end field of previoussimulation

initial field

landuse

chemistry

Resolution 0.25 x 0.25 degree8 horizontal layersHourly concentrations of44 gases and aerosols

by Qiang Zhangand David Streets

INTEX-B Emissions

Use of Chimere Results

• Forecast of air quality in China for large urban areas– www.amfic.eu/bulletin

• Background values for street level model CERC– www.beijingairquality.cn/

• Background values for regional model VITO– www.vito.be/amfic

• Air quality forecast during Olympic Games– www.knmi.nl/beijing2008

www.amfic.eu/bulletin

www.amfic.eu statistics

Jan 2009 Feb 2009 Mar 2009 Apr 2009 May 2009 Jun 2009*

Totaal 3256 1021 6002 3743 9072 3044

articles 51 69 148 173 120 49

articles.php 15 15 64 51 42 19

bulletin 169 155 1075 1073 1420 616

forecast.php 15 14 54 44 49 9

grounddata.php 8 6 17 19 13 3

index.php 18 22 102 83 62 25

internal 20 61 69 31 389 374

links.php 21 21 69 71 28 19

members.php 20 21 92 62 61 11

overpass_data 1150 1127 1533 303

satellite.php 2760 458 2716 682 5038 1563

validationdata.php 14 21 71 74 50 17

*) up to 16 June

2Validation, Nocturnal Values

Measurements by BBC

PM10 MODEL vs BBC Measurements

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PM10 Chimere 13h LT

PM10 BBC

Olympic Games

http://news.bbc.co.uk/2/hi/in_pictures/7506925.stmDaily PM10 measurements at 13h in central Beijing

Comparison with Beijing

Diurnal variation

Measurements (W.-x. Wang et al., 2008Air Qual Atmos Health)

Chimere (0.25°×0.25°)

Measured August 7 to September 30, 2007at Chinese Research Academy of Environmental Sciences

Diurnal profile PM10

Beijing (Aug-Sep 2007) Hong Kong (Aug-Sep 2007)

Time series Hong Kong

PM10 at 15h local time PM10 at 03h local time

19 Aug

26 Aug 6-7 Sep

• Nocturnal boundary layer height too low over megacities (e.g. BLH=20 m for Beijing)

• Trace gases not well mixed due to low vertical diffusion coefficient (e.g. Kz=0.1 m2/s for Beijing)

Caused by a lack of Urban Heat Island Effect: too low sensible heat flux over megacity.

Taking BLH=750 m and Kz=1 m2/s for Beijing decreases nocturnal PM10 with 25-30%

3Future Steps

• Improvements of model– Nocturnal boundary layer– Aerosols– …

• Improvement of emissions– Higher resolution (VITO) – Assimilation of satellite data– Better diurnal cycle by sector– …

Future Steps

Desaggregation of emissions

Original INTEX-B (0.5x0.5)Desaggregated by VITO to

AMFIC grid (0.25x0.25)

Conclusions

• Chimere model is successfully implemented• Daily operational forecasts are available on

website http://www.amfic.eu/bulletin

• Results validate well, but high nocturnal values due to unrealistic boundary layer for megacity.

• More ground sources needed for further validation!

• Model and emissions are to be improved

Thank you!